What Do an Earthworm and a Cockroach Have in Common?
WouterAn earthworm and a cockroach share a number of characteristics. Both are segmented and have a pair of appendages on each segment. Their nervous systems are similar. They also share a tubular dorsal heart. Lastly, both have sexual dimorphism.
Earthworms are clay-coloured and contain a porphyrin pigment. This protects the worm from bright light. Their bodies contain three different regions: the head, legs, and abdomen. The head and gills are on the head, whereas the mouth and anus are located on the back. The mouth is larger than the anus. The male earthworm has a ureter located in the 14th segment, while the female has a gill on the 18th segment. They also have a dark mid-dorsal line and a set of blood vessels on the body wall.
Cockroaches are dioecious. Their bodies are segmented into three thorax segments and six segments in the abdomen. This makes their nervous system a highly distributed system. Cockroaches are nocturnal omnivores. The head is triangular in shape and contains a pair of compound eyes and antennae. The thorax contains the prothorax and mesothorax.
The mouths of both creatures have peristomium surrounding them. These segments are covered with a protective cuticle, which is a waxy covering secreted by the epidermis. As a result, gas exchange is impossible directly across the skin, but instead occurs through diffusion across the gut wall. This is possible because of a space between the body wall and the digestive tract.
